CN110742582A

CN110742582A - Binary image segmentation method for catheter polarization-sensitive optical coherence tomography

Info

Publication number: CN110742582A
Application number: CN201910954715.3A
Authority: CN
Inventors: 黄进宇; 陈韵岱; 陆维; 周亮; 童国新; 殷聪国; 陶魁园; 刘子旭
Original assignee: NANJING WOFUMAN MEDICAL TECHNOLOGY Co Ltd
Current assignee: NANJING WOFUMAN MEDICAL TECHNOLOGY Co Ltd
Priority date: 2019-10-09
Filing date: 2019-10-09
Publication date: 2020-02-04

Abstract

A two-state image segmentation method for catheter polarization-sensitive optical coherence tomography resolution is characterized in that a cross-correlation method is adopted, the same A-Line data of an H channel and a V channel are subjected to cross-correlation operation, the A-Scan data of two input polarization states are included, the initial positions of the data of the two input polarization states are adjusted according to the offset of a cross-correlation peak, so that the first effective data points of the two input polarization states are aligned, and finally, the four electric field data forming a measurement Jones matrix are from the same depth position of the same sample in the next polarization resolution. The method can ensure the accurate registration of the four polarization components and ensure that the data of the four electric fields forming the measurement Jones matrix are from the same depth position of the same sample.

Description

Binary image segmentation method for catheter polarization-sensitive optical coherence tomography

Technical Field

The invention relates to the field of catheter imaging covering cardiovascular and cerebrovascular systems and the like by catheter Optical Coherence Tomography (OCT), in particular to birefringence information of a demodulation sample in a catheter Polarization-sensitive OCT (Polarization-sensitive OCT) image, namely a PS-OCT image, and specifically relates to a binary image segmentation method for catheter Polarization-sensitive OCT imaging demodulation.

Background

The catheter OCT imaging technology is a blood vessel imaging method with the highest image resolution at present, particularly the catheter PS-OCT imaging technology, can solve the medical problem that the stability of atherosclerotic plaques is difficult to judge in vivo, in real time and rapidly, and can improve the prevention and treatment effect of atherosclerotic diseases. However, the existing OCT system has reached a level that may determine the property of the tissue plaque in terms of resolution, but is still insufficient in terms of tissue penetration ability, image sharpness, and accuracy of tissue plaque type determination, and using the PS-OCT technology, improving the performance of the related technology is a key direction for development of the OCT system, and is also a necessary way to solve the aforementioned key scientific problems.

In catheter OCT, catheter PS-OCT is an extension of catheter OCT technology, which provides a quantitative measure of tissue birefringence properties. The birefringence of light changes the polarization state of light and can be associated with proteins and biological macromolecules with oriented structures such as collagen, actin, and the like. The enhanced birefringence phenomenon of catheter PS-OCT is closely related to the existence of a large amount of thick collagen fibers or intimal smooth muscle cells, so that the high-resolution detection of catheter PS-OCT imaging can be applied to the enhanced plaque stability measurement. In addition, catheter PS-OCT systems have the potential to assess plaque collagen and differentiate normal intima, fibrous plaque, lipid plaque, and calcified plaque, among others.

Therefore, the catheter polarization sensitive optical coherence tomography system and the demodulation method well solve the problems. In the system, a fast scanning light source is adopted as a light source, a polarization-maintaining optical fiber is adopted in the system to generate orthogonal polarization state delay, polarization diversity acquisition is carried out through a polarization beam splitter, and polarization diversity imaging of two orthogonal input polarization states is presented in one image at the same time. The demodulation method finally realizes the vascular birefringence imaging through a series of steps of polarization leveling, background signal elimination, spectrum shaping, two-state dispersion elimination, interpolation Fourier transform, image segmentation, reference surface selection, polarization settlement, polar coordinate conversion to Cartesian coordinates and the like. The exact description should be image segmentation and precise alignment: the image segmentation is to divide the signals of H1 and H2 (V1 and V2), and the step is divided into two parts from the middle according to the length of the original signals. H1+ H2 is an H channel signal, and V1+ V2 is a V channel signal, and since two polarization states change due to high-speed rotation of the optical fiber conduit during the acquisition process, the first effective data positions of the four polarization components are different, that is, the four polarization components acquired at the same coordinate position have different corresponding sample depths. Therefore, precise registration of the four polarization components is required before the polarization solution is performed.

Disclosure of Invention

The invention aims to solve the problem that the existing OCT catheter optical coherence tomography system can only acquire blood vessel intensity information, and provides a method for binary image segmentation for catheter polarization-sensitive optical coherence tomography resolution.

The technical scheme of the invention is as follows:

a two-state image segmentation method for catheter polarization-sensitive optical coherence tomography resolution is characterized in that a cross-correlation method is adopted, the same A-Line data of an H channel and a V channel are subjected to cross-correlation operation, the A-Scan data of two input polarization states are included, the initial positions of the data of the two input polarization states are adjusted according to the offset of a cross-correlation peak, so that the first effective data points of the two input polarization states are aligned, and finally, the four electric field data forming a measurement Jones matrix are from the same depth position of the same sample in the next polarization resolution.

The invention has the beneficial effects that:

the method can ensure the accurate registration of the four polarization components and ensure that the data of the four electric fields forming the measurement Jones matrix are from the same depth position of the same sample.

Drawings

FIG. 1 is a flow chart of a catheter polarization-sensitive optical coherence tomography demodulation method related to the present invention.

Detailed Description

The invention is further described below with reference to the figures and examples.

A two-state image segmentation method for catheter polarization sensitive optical coherence tomography resolution adopts a cross-correlation method to perform cross-correlation operation on the same A-Line data of an H channel and a V channel, wherein the A-Scan data of two input polarization states are included, and the initial positions of the data of the two input polarization states are adjusted according to the offset of a cross-correlation peak so as to ensure that the first effective data points of the two input polarization states are aligned and finally ensure that four electric field data forming a measurement Jones matrix are from the same depth position of the same sample in the next polarization resolution.

The flow chart of the demodulation method of the catheter polarization-sensitive optical coherence tomography related to the invention is shown in figure 1, and the demodulation method comprises a series of steps of polarization leveling, background signal elimination, spectrum shaping, two-state dispersion elimination, interpolation Fourier transform, image segmentation, reference surface selection, polarization settlement, polar coordinate conversion to Cartesian coordinate and the like to finally realize vascular birefringence imaging,

the parts not involved in the present invention are the same as or can be implemented using the prior art.

Claims

1. A two-state image segmentation method for catheter polarization-sensitive optical coherence tomography resolution is characterized in that a cross-correlation method is adopted, the same A-Line data of an H channel and a V channel are subjected to cross-correlation operation, the A-Scan data of two input polarization states are included, the initial positions of the data of the two input polarization states are adjusted according to the offset of a cross-correlation peak, so that the first effective data points of the two input polarization states are aligned, and finally, the four electric field data forming a measurement Jones matrix are from the same depth position of the same sample in the next polarization resolution.